One common theme is the idea of the Hulk finding acceptance among the female characters. Since he's often seen as an outcast, in these fanfictions, the female characters welcome him into their group. Another theme is teamwork. They all have to work together to face various villains or challenges in the Marvel universe.
Spiderman is the key, of course. In addition to the well - known female characters from the Spider - Man universe, there might be other characters from the Marvel world who cross paths with him and end up in the harem. For instance, Black Cat could be a likely candidate. She has that alluring and mysterious personality that would fit well in this kind of scenario. Also, characters from different dimensions or alternate universes could be brought in, adding an element of the unexpected to the harem and the overall story.
One interesting plotline could be Spiderman having to balance his superhero duties with the complex relationships in the harem. Maybe he has to keep his identity secret from some of the harem members while also protecting them from villains.
A common plot is that Spider Man's harem is formed due to some kind of magical or scientific experiment gone wrong. For example, a device meant to create a new type of energy instead creates a bond between him and several Marvel women. As a result, they have to learn to live together and deal with the new dynamic, which includes fighting bad guys and exploring their new relationships.
The characters interact in various ways. Spider Man is often the central figure, and the female characters in the harem might start off as just friends or allies. For example, Mary Jane might be initially jealous if other characters join the harem. But as the story progresses, they learn to work together and support each other. They might train together to fight villains, like Spider Man teaching some of the less experienced characters new combat moves.
Well, there's 'The Hulk's Harem Adventure'. It's a story where the Hulk, in his own brute yet endearing way, forms a special bond with a group of Marvel female characters. It has a lot of action scenes intertwined with the development of their relationships. Also, 'Hulk's Harem of Heroes' is quite interesting. It shows how the Hulk's presence affects the female heroes in the Marvel universe and how they all come together in an unexpected way.
One common theme is the exploration of relationships. Since it's a harem concept, there's a focus on how the main character interacts with multiple love interests. Another theme is power dynamics. For example, in a fanfiction where a superhero has a harem, it might show how their powers affect their relationships.
I really like 'Naruto and the Marvel Harem: A Fusion of Worlds'. In this fanfiction, Naruto's ninja skills blend well with the Marvel setting. The harem aspect is also well - written, with characters from both universes having interesting interactions. There are also some fanfictions that focus on how Naruto adapts to the Marvel world while building his harem, which are quite engaging.